The present invention relates to a chord information generating apparatus and a chord information generating method for performing an automatic accompaniment with chords (hereinafter called "chord accompaniment").
One known automatic accompaniment apparatus generates accompaniment notes based on automatic accompaniment pattern data (hereinafter simply called "pattern data") previously stored in a memory and the key depression state on a keyboard instrument. This automatic accompaniment apparatus includes a chord information generating apparatus. The chord information generating apparatus comprises a chord discrimination portion for discriminating a chord consisting of a chord type and a chord root, and an accompaniment notes producing portion for preparing a plurality of accompaniment notes based on the results of the discrimination and based on the pattern data previously stored in the memory.
A keyboard type electronic musical instrument for which the automatic accompaniment apparatus of this type is adapted has, for example, an upper keyboard assigned for melodies and a lower keyboard assigned for chords. Therefore, a player can play a melody with the upper keyboard while generating chord accompaniment notes by designating chords with the lower keyboard.
Conventional automatic accompaniment apparatuses use several chord designating methods. In the first method, when three or more keys are pressed in a predetermined chord form, the chord information generating apparatus included in the automatic accompaniment apparatus discriminates a chord consisting of a chord root and a chord type based on the pressed keys, and then generates chord information based on this chord. Because this first method requires that a player should press three or more keys in accordance with the progress of music, it is difficult for beginners or inexperienced players. The first method is therefore mainly used by skilled players.
The second method designates a chord with one key or two keys, and is mainly used by beginners or inexperienced players. In the second method, when only one key is depressed, the note name of the depressed key directly becomes a chord root and the chord type becomes major (fixed). When two keys are depressed, the note name on, for example, the bass side key becomes a chord root and a chord type becomes minor when the keys are depressed in minor third and major when the keys are depressed in major third. Based on the chord root and the chord type, chord information for generating three or more chord tones is generated.
There is another known chord designating method for beginners, called "one-finger chord designation", which designates a chord with one key alone. In this method, a device called "touch bar" is used. According to this chord designation method, the note name of the depressed key becomes a chord root and a chord type is specified by the touch bar. Based on the chord root and the chord type, chord information for generating three or more chord tones is generated.
The chord designation method for beginners and the chord designation method for skilled players are prepared for most of the conventional automatic accompaniment apparatuses as mentioned above. The player previously specifies which chord designation method to use by operating a special device provided on an operation panel.
In general, beginners use one key or two keys to designate a chord, while skilled players use three or more keys to designate a chord. This suggests that it is possible to automatically determine whether the player is a beginner or a skilled person.
Beginners, who can depress just one or two keys only, demand that three or more chord tones be produced as tones from the lower keyboard by the depression of one or two keys. Skilled persons, on the other hand, desire that the tones of depressed keys (even if no chord is formed) be directly produced as tones from the lower keyboard.